1. Field of the Invention
This invention relates to a technique of reducing the vibration of a motor produced when the motor is incorporated in a lens barrel to drive a diaphragm, shutter, or lens.
2. Description of the Prior Art
In the past there was the technique of incorporating into the photographic lens mounting a motor for driving the diaphragm or the lens. This motor was either a coreless motor causing little vibration, or a moving coil type diaphragm drive device, or the so-called "autoiris". There is a proposal for using a stepping motor for driving the diaphragm or the like. But the stepping motor has significant vibrations due to the cogging as it is driven to rotate. Particularly, in the case of cameras which are high precision machines, when vibrations are generated in the lens barrel, not only a bad influence is given to the internal mechanisms of the camera but also the photographer is annoyed at unpleasant feeling and cannot even concentrate his mind on shooting the object. Nevertheless, no proposal concerning counter-measures against the vibrations arising when the stepping motor is incorporated into the lens barrel has yet been made.